1. Field of the Invention
The present invention relates to a diffusion transfer color photographic material, more particularly, to a color photographic material for a diffusion transfer process using a primary aromatic amino color developing agent and to process therefor.
2. Description of the Prior Art
Color photographic materials for a diffusion transfer process using a primary aromatic amino color developing agent are disclosed in many patents and patent applications as shown below, and dye image forming processes, dye image providing materials, layer structures, and layer arrangements are well known, and in any case dye images are formed by the reaction of the dye image providing materials and the oxidation product of a primary aromatic amino color developing agent. In such a color diffusion transfer process, it is necessary that the dye image be stable, that is, whether the photosensitive element is separated or not from the image receiving element after the dye images formed are transferred to the image receiving element, the dye images formed in the image receiving element are very unstable when processing composition remains in the spread state therein, and the dye images are usually faded or blank areas, that is, areas to which dye images were not transferred are stained with the passage of time.
A few techniques for improving the aforementioned faults in the color development have been reported. For instance, Japanese Patent Application (OPI) 5424/1973 teaches that the addition of an aldehyde-bisulfite addition product is effective to prevent the formation of stains in the blank areas. It is believed that the additive reacts with excessive primary aromatic amino color developing agent remaining (which has not been used in the development) to form a colorless product so that the formation of yellowish-brown stains caused by the diffusion of unreacted primary aromatic amino color developing agent into the image receiving element is reduced. Also, Japanese Patent Application (OPI) 15,134/1972 teaches that the addition of an isocyanate-bisulfite addition product to a polymer binder is effective to prevent the formation of stains in blank areas. It is believed that the formation of stains is presented by the same action as above. Furthermore, Japanese Patent Application (OPI) 3836/1973 teaches that the addition of a bis(vinylsulfonylalkyl) derivative or a polymer thereof is also effective for the aforesaid purpose, and in this case it is also believed that the formation of stains is restrained by the same action as above.
As mentioned above, the addition of an aldehyde-bisulfite addition product, an isocyanate-bisulfite addition product, a bis(vinylsulfonylalkyl) derivative or the polymer thereof may be effective to prevent stains in blank areas, but the addition of the aforesaid materials has a low effect for the prevention of fading of dye images.
Furthermore, the stabilization of dye images is generally very important in color photographic materials for a diffusion transfer process using a primary aromatic amino color developing agent, that is, in general color photography a developing solution (it is well known that the solution has a bad influence on the stabilization of dye images) is supplied to an exposed photosensitive element from a processing bath such as an automatic developing machine but is removed therefrom in a post treatment such as fix, wash, bleach, etc., after development. That is, in general color photography operations which are preferred for the stabilization of color images are employed but in a diffusion transfer color photographic system the processing composition is left on the image bearing image receiving element after development, and thus, as will be easily understood, the color images formed become unstable.